Pollination, fertilisation and germination

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This is a brief presentation about pollination, fertilisation and germination.
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Pollination, fertilisation and germination

  1. 1. Pollination, fertilisation and germination Life Cycle of a Flowering Plant
  2. 2. Parts of a flower
  3. 3. Reproductive parts <ul><li>There are sex cells in </li></ul><ul><li>pollen grains (male cells) </li></ul><ul><li>ovules (female cells) </li></ul>
  4. 4. By fertilization <ul><li>For fruits and seeds to form, male and female sex cells must meet and fuse . </li></ul><ul><li>Since male and female sex cells are involved, this is called “ sexual reproduction ”. </li></ul><ul><li>When the male cells meet with the female cell, they join together…this is called fertilization . </li></ul>
  5. 5. Pollination <ul><li>Definition: </li></ul><ul><li>The transfer of pollen grains from the anther to the stigma of a flower. </li></ul>
  6. 6. Pollination <ul><li>Two types of pollination </li></ul><ul><li>Self-pollination </li></ul><ul><li>Cross-pollination </li></ul>
  7. 7. Pollination <ul><li>Self-pollination </li></ul><ul><li>Transfer of pollen grains within one flower: </li></ul><ul><li>One flower. </li></ul><ul><li>Pollen grains from the anther are transferred onto the stigma. </li></ul>
  8. 8. Pollination <ul><li>Cross-pollination </li></ul><ul><li>Transfer of pollen grains from one flower to </li></ul><ul><li>another: </li></ul><ul><li>Two similar flowers. </li></ul><ul><li>Pollen grains from the anther of one flower are transferred onto the stigma of the other flower. </li></ul>
  9. 9. Pollen <ul><li>Pollen of different plants have different shapes and sizes. </li></ul><ul><li>Pollen are small and light so that they can be carried by the agents of pollination. </li></ul>
  10. 10. Pollen
  11. 11. Agents of pollination <ul><li>Plants generally do not transfer the pollen from one flower to another by themselves. </li></ul><ul><li>Although a few plants do have self-pollination – pollen from flower’s anther pollinating its own stigma. </li></ul><ul><li>These plants need agents of pollination to help them. </li></ul>
  12. 12. Agents of pollination <ul><li>Insects (bees) </li></ul><ul><li>Other animals (birds and bats) </li></ul><ul><li>Wind </li></ul>
  13. 13. Agents of pollination <ul><li>Insects </li></ul><ul><li>pollen will stick to parts of insects’ bodies, e.g. pollen “bags” situated on the legs of bees. </li></ul>
  14. 14. Agents of pollination <ul><li>Other animals (birds) </li></ul><ul><li>these animals are usually nectar-drinking animals like sunbirds. </li></ul>
  15. 15. Agents of pollination <ul><li>Other animals (bats) </li></ul><ul><li>these animals are usually nectar-drinking animals like nectar-feeding bats. </li></ul>
  16. 16. Agents of pollination <ul><li>Wind </li></ul><ul><li>pollen tend to be smaller and lighter in order to be carried by the wind. </li></ul>
  17. 17. Fertilisation <ul><li>When the male sex cells join with the female sex cells within the ovule. </li></ul><ul><li>The resulting embryo then develops into a seed. </li></ul><ul><li>Unfertilised ovules cannot become seeds. </li></ul><ul><li>Fertilised ovules become seeds. </li></ul>
  18. 18. Germination <ul><li>The growth of the root through the seed coat. </li></ul>
  19. 19. Germination
  20. 20. Steps in germination: <ul><li>When a seed lands on a place with sufficient warmth, water and air , it starts to germinate. </li></ul><ul><li>Sunlight is not necessary for germination. </li></ul><ul><li>1. The root of the baby plant grows out of the seed to form a seedling. The seed coat falls on the ground. </li></ul><ul><li>2. The shoot appears and breaks through the soil and the first leaves show . The cotyledons fall on the ground. </li></ul><ul><li>3. The young plant now can make its own food with the sunlight by photosynthesis. </li></ul>
  21. 21. Germination <ul><li>When a seed lands on a place with sufficient warmth, water and air , it starts to germinate. </li></ul><ul><li>Sunlight is not necessary for germination. </li></ul><ul><li>First, the root of the baby plant grows out of the seed to form a seedling. </li></ul><ul><li>During this stage, the seedling cannot make its own food. </li></ul><ul><li>It gets its energy from the food stored in its seed leaves. </li></ul>
  22. 22. Germination <ul><li>Seed leaves are the parts of a seed that protect the baby plant. </li></ul><ul><li>Next, the shoot appears and breaks through the soil and the first leaves unfold. </li></ul><ul><li>The young plant is now able to make its own food as the green leaves makes food in the sunlight (photosynthesis). </li></ul><ul><li>Note: seed leaves are the parts of a seed that protect the baby plant, leaves are the part of the plant that manufactures food. </li></ul>
  23. 23. Remember: <ul><li>Pollination </li></ul><ul><li>- the transfer of pollen grains from the </li></ul><ul><li>anther to the stigma of a flower. </li></ul><ul><li>Agents of pollination </li></ul><ul><li>- animals that help plants transfer the </li></ul><ul><li>pollen from one flower to another (insects, animals, water, wind) </li></ul><ul><li>Fertilisation </li></ul><ul><li>- when the male sex cells join with the female </li></ul><ul><li>sex cells within the ovule. </li></ul><ul><li>Germination </li></ul><ul><li>- the growth of the root through the seed coat. </li></ul>
  24. 24. The end

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